This invention relates generally to devices used to evaluate gemstones and, more particularly, to devices and methods that permit the light performance of a gemstone to be evaluated.
The commercial value of a gemstone depends upon the gemstone weight, cut, clarity and color. Each characteristic has an effect on the price of the gemstone. Thus the evaluation of these parameters is critical to setting the price. Weight is measured objectively, clarity is a subjective measurement made by evaluating the inclusions through a microscope, and color is evaluated subjectively against a master color set. Currently cut is evaluated by measuring the cut angles and comparing the angles to a theoretical ideal standard. If the cut angles approach the ideal standard, in theory the gemstone, particularly a diamond, will have high brilliance and dispersive characteristics otherwise known as brilliancy or light performance.
When illuminated, a diamond returns light in the form of white light and colored light at various intensities. Sparkle is the result of light being reflected and refracted by the stone and is considered to be a major factor in a stone""s beauty. Other contributing factors in a stone""s, particularly a diamond""s, beauty include brilliance, scintillation, fire, and brightness. These factors taken together describe the light performance of a gemstone.
When purchasing a diamond, to evaluate its light performance, and therefore its beauty, standard practice calls for tilting the diamond in a well-lit room or under a diamond light to change the angle that the light enters the stone. This causes the stone to sparkle but is generally an insufficient method to demonstrate its beauty.
U.S. Pat. No. 5,615,005, issued to Valente et al., provides a device and method for grading gemstones. The device utilizes a band pass filter and detector array to obtain the spectral response of a complete image. The image of the gemstone is transmitted through a processing system which includes sequential selection of individual wavelengths, detecting the amplitude of each wavelength, and converting the amplitude signal into a form for subsequent processing. While effective, this method may prove to be expensive and perform functionally beyond what may be desired.
Accordingly, a need exists for an improved device and method for viewing stones, and more specifically, diamonds, prior to purchase. Further, there is a need to be able to view and compare the light performance of diamonds prior to purchase in a controlled and consistent manner. Further, there is a need for controlled and consistent viewing and evaluation of light performance at the point of purchase. It would also be desirable to have a relatively inexpensive device for evaluating light performance.
Therefore, it is an object of the present invention to provide a device for viewing gemstones, and in particular, diamonds. It is an additional object of the present invention to provide a diamond-viewing device that enables viewing in a controlled and consistent manner and which enables one to better view a diamond""s beauty. It is a further object of the present invention to provide a diamond-viewing device that allows such viewing to be readily available at the point of purchase. It is a further object of the present invention to provide a diamond-viewing device that is efficient and relatively inexpensive for the diamond seller to have on hand. It is a further object of the present invention to provide a diamond-viewing device that overcomes the disadvantages of the prior art.
The diamond viewer of the present invention provides the above-mentioned and many additional objects by providing a diamond viewer that allows a person to view the light performance of a diamond, and therefore its beauty, in a controlled environment. The diamond viewer allows viewing of the light performance of a diamond by controlling the light used for viewing to be consistent (which also aids in side-by-side evaluations), by changing the angle by which the light enters the stone by means of a moveable light source above the diamond, as well as placing the diamond within a light control structure or other light control structure, preferably made of reflective material, to better see the diamond""s secondary colors and sparkle.
The diamond viewer of the present invention has a light unit attached to a mounting bracket. The mounting bracket is dependent from a threaded shaft that transmits rotational movement of a hand wheel into vertical movement, allowing the mounting bracket and light ring to move vertically. A base is provided to allow for secure and consistent placement of a diamond during viewing. As indicated, a light control structure is positioned over the diamond. An aperture is formed in the light control structure to allow light from the light unit to enter. The diamond is positioned under the center of the light unit and light control structure. The light control structure is opaque, and shaped with an aperture in its top such as to create proper lighting angles to enhance the diamond""s sparkle and beauty during viewing. The angle at which the light illuminates the diamond is produced by a combination of factors, namely the size of the aperture in the light control structure, the diameter of the light unit, and the distance between the light unit and the diamond.
The diamond viewer functions when the user places the diamond under the light control structure. Light from the light unit positioned above the light control structure enters the diamond through the aperture in the light control structure. As stated, the angle at which the light hits the diamond is governed by the relative size of the aperture in the light control structure, the diameter of the light unit, and the distance from the light unit to the diamond. The light unit can be vertically repositioned by use of the hand wheel. By then viewing the diamond, the purchaser is better able to see the diamond""s sparkle, and overall light performance, in a controlled and consistent setting.
As mentioned, currently to evaluate a diamond""s beauty when purchasing, a user would tilt a diamond in a well-lit room or under a diamond light. By tilting the stone, essentially the user is changing the angle that the light enters the stone. This method is confusing to the customer and does an inconsistent job showing the diamond""s beauty. The diamond viewer allows a person to view the light performance of a diamond in a consistent manner. The diamond viewer changes the angle that the light enters the stone by moving the vertical position of a light source above the diamond. Because the diamond viewer places the diamond in a controlled lighting environment, the diamond sparkles in a more brilliant manner. A person can then evaluate how beautiful a diamond is and make a value/price decision.
The diamond viewer is advantageous to both the retailer and the consumer. The device will illuminate the diamond in such a way that the diamond""s directly refracted light (i.e., white light), as well as the dispersed light (i.e., spectral colors) are readily available to the consumer. This will, of course, also enable the consumer to better make a value/price decision, and to understand why price and certificates are not the only consideration. And, because the retailer is able to more easily demonstrate the beauty of the diamond, the invention will allow the retailer to more easily and better explain the correlation of price and value, and, subsequently, sell more high-end center stones.
While the present invention can be used to view diamonds at point of consumption, it should be noted that the present invention could be adapted for viewing other stones at various points in their evaluation process.
In sum, the present invention represents a significant improvement over the prior art in many ways. The diamond viewer in accordance with the present invention allows for controlled and efficient diamond viewing at the point of consumption, and overcomes the disadvantages of the prior art. These and other objects and advantages of the present invention will become apparent from the detailed description and accompanying drawings.